Inhibition of the NF-κB Signaling Pathway Improves Cigarette Mainstream Smoke-Induced Lung Injury and Gut Microbiota Disturbance

Currently,cigarette smoke(CS)remains a major contributor to disease morbidity and mortality.CS can be divided into cigarette mainstream smoke(CMS)and side-stream smoke,depending on where it is produced by burning tobacco^([1]).CMS is inhaled by smokers from the filter end during cigarette combustion and is strongly associated with the development of several diseases^([2-4]).

Investigation and Analysis of Three Nitrogen Pollution in Groundwater in Ledong, Hainan Province

[Objectives]This study was conducted to systematically monitor the contents of "three nitrogen",including ammonia nitrogen (NH4^+-N),nitrate nitrogen (NO3^--N) and nitrite nitrogen (NO2^--N) in groundwater in Ledong and analyze the reasons.[Methods]A total of 30 sampling points were set up in Ledong,including 22 ground waters and 8 surface waters.NO3^--N,NH4^+-N,NO2^--N and pH indicators were detected.[Results]① There is a problem of excessive nitrogen in the groundwater of Ledong,Hainan.NH4^+-N and NO3^--N exceeded the standards severely,and the over-standard rates were 27.27% and 13.64%,respectively.NO2^--N didn't exceed the standard.Among them,the highest concentration of NH4^+-N was up to 2.692 mg/L;and the highest concentration of NO3^--N reached 24.071 mg/L.② The pollution trends of NH4^+-N and NO2^--N in Ledong County were similar,and NO3^--N had no similarity.③ There was a regional difference in the groundwater three nitrogen in Ledong,Hainan.The pollution level near the farmland was greater than that far from the farmland.The pollution level near the farm area was greater than that far from the farm area.In addition,in combination with the layout of the sampling points and the test results,it was not found that the area far from the coastline would be lower than the area near the coastline in the pollution level.④ The main reasons for the excessive nitrogen in the groundwater of Ledong,Hainan are farmland fertilization,random discharge of domestic sewage,discharge of aquaculture wastewater,and discharge of industrial water at will.[Conclusions]This study is of great significance to safe prevention and control of groundwater in Ledong.

Time-history performance optimization of flapping wing motion using a deep learning based prediction model

Flapping Wing Micro Aerial Vehicles(FWMAVs)have caused great concern in various fields because of their high efficiency and maneuverability.Flapping wing motion is a very important factor that affects the performance of the aircraft,and previous works have always focused on the time-averaged performance optimization.However,the time-history performance is equally important in the design of motion mechanism and flight control system.In this paper,a time-history performance optimization framework based on deep learning and multi-island genetic algorithm is presented,which is designed in order to obtain the optimal two-dimensional flapping wing motion.Firstly,the training dataset for deep learning neural network is constructed based on a validated computational fluid dynamics method.The aerodynamic surrogate model for flapping wing is obtained after the convergence of training.The surrogate model is tested and proved to be able to accurately and quickly predict the time-history curves of lift,thrust and moment.Secondly,the optimization framework is used to optimize the flapping wing motion in two specific cases,in which the optimized propulsive efficiencies have been improved by over 40%compared with the baselines.Thirdly,a dimensionless parameter C_(variation)is proposed to describe the variation of the time-history characteristics,and it is found that C_(variation)of lift varies significantly even under close time-averaged performances.Considering the importance of time-history performance in practical applications,the optimization that integrates the propulsion efficiency as well as C_(variation)is carried out.The final optimal flapping wing motion balances good time-averaged and time-history performance.

Mechanism analysis of hysteretic aerodynamic characteristics on variable-sweep wings

Variable-sweep wings have large shape-changing capabilities and wide flight envelops,which are considered as one of the most promising directions for intelligent morphing UAVs.Aerodynamic investigations always focus on several static states in the varying sweep process,which ignore the unsteady aerodynamic characteristics.However,deviations to static aerodynamic forces are inevitably caused by dynamic sweep motion.In this work,first,unsteady aerodynamic characteristics on a typical variable-sweep UAV with large aspect ratio were analyzed.Then,deep mechanism of unsteady aerodynamic characteristics in the varying sweep process was studied.Finally,numerical simulation method integrated with structured moving overset grids was applied to solve the unsteady fluid of varying sweep process.The simulation results of a sweep forward-backward circle show a distinct dynamic hysteresis loop surrounding the static data for the aerodynamic forces.Compared with the static lift coefficients,at the same sweep angles,dynamic lift coefficient in sweep forward process are all smaller,while dynamic sweep backward lift coefficient are all larger.In addition,dynamic deviations to static lift coefficient are positively related with the varying sweep speeds.Mechanism study on the unsteady aerodynamic characteristics indicates that three key factors lead to the dynamic hysteresis loop in varying sweep process.They are the effects of additional velocity caused by varying sweep motion,the effects of flow hysteresis and viscosity.The additional velocity induced by sweep motion affects the transversal flow direction along the wing and the effective angle of attack at the airfoil profile.The physical properties of flow,the hysteresis and viscosity affect the unsteady aerodynamic characteristics by flow separation and induced vortexes.